A magnetoresistive element is used in, e.g., a memory cell of a magnetic random access memory, or an LSI such as a spin-transfer-torque switching field-effect transistor (FET) of a reconfigurable logic circuit. In this case, the magnetoresistive element is patterned into a pillar. This patterning of the magnetoresistive element is performed using so-called physical etching because the magnetoresistive element is made of a hard material.
Since, however, physical etching is an etching method that physically scrapes off a material to be etched by colliding atoms against the material, the material is re-deposited on the sidewall of the patterned magnetoresistive element, i.e., a so-called, re-deposition phenomenon occurs. This re-deposition phenomenon causes a shortcircuit between a recording layer and reference layer of the magnetoresistive element.
To prevent this shortcircuit, a process of oxidizing the re-deposition layer formed on the sidewall of the magnetoresistive element during or after patterning of the magnetoresistive element has been developed. If this process is adopted, however, the edges of the recording layer and reference layer of the magnetoresistive element are also unintentionally oxidized. This deteriorates the characteristics (e.g., increases the element resistance) of the magnetoresistive element.